Mechanical system comprising a device for connection between a wearing part and the support thereof, heavy-construction machine bucket, and method for implementing said system

ABSTRACT

A mechanical system includes a support, a wearing part and a device for interconnecting them. The support includes two openings on either side of a housing for receiving the device. The device includes a threaded key, a nut, and an elastic sheath having a wall adjustable by deformation. Each opening includes a first part centered on a central axis of the housing and radially extending by a maximum of 180° around the central axis, and a second part connected to the first part and radially staggered in relation to the central axis. In the insertion configuration, the device passes through the second part and does not exert any locking force on the wearing part. In the locking configuration, the axis of the key is essentially aligned with the central axis, the sheath wall is adjusted in the housing and the device exerts locking forces on the wearing part.

The present invention relates to a mechanical system comprising a support, a wearing part and a connection device between the wearing part and its support, in particular a tooth and its support belonging to a piece of heavy-construction machine equipment. The invention also relates to a heavy-construction machine bucket comprising at least one such system. Lastly, the invention relates to a method for implementing such a system.

The invention relates to the field of heavy-construction machine equipment, in particular the buckets, hoppers or other receptacles that may scrape, remove and transport materials so that they may be evacuated from a given location to other workstations using heavy-construction machines.

In a known manner, a bucket includes a leading blade equipped with wearing parts provided for their ability to penetrate the material and protect the other elements making up the bucket. Fastened on the leading blades are support-adapters having a profile nose, while the wearing parts are teeth or shields that are positioned on the support-adapter using a precise connection. This connection is temporary so that the wearing parts can be replaced after wear.

The connection between the wearing part and its support may be done by keying. To be high-performing, the keying devices must provide a rigid connection of the elements that they join. Traditionally, the assembly and disassembly of the keyings is done by using striking tools, which create a risk of injury for operators.

Also known are keying devices that do not require the use of striking tools. In that case, special restrictive equipment is necessary, in particular to disassemble the wearing part. Furthermore, the known devices are complex to manufacture and use.

FR-A-2 878 871 describes a keying connection device between a wearing part and its support. In the example of FIGS. 5 to 7, the device comprises two cylinders that screw onto one another and a rubber sheath placed between them. The screwing of the two cylinders deforms the sheath in a housing of the support, while the cylinders are housed in orifices of the wearing part. The connection provided by such a device lacks rigidity, efficiency and reliability. In particular, the cylinders are not systematically in a rear contact position to ensure retention of the tooth.

US-A-2007 261 278 describes another connection device between a wearing part and its support. The device comprises a deformable sheath between two washers, which in turn are positioned between two cylindrical members. Screwing the two members deforms the sheath in a housing of the support. This connection device has a similar operation, but a more complex construction compared to the earlier one.

The aim of the present invention is to propose an improved connection device, making it possible to eliminate striking operations for the assembly and disassembly of the wearing parts. In particular, the invention relates to a connection device by keying that is high-performing, reliable, strong, simple and practical.

To that end, the invention relates to a mechanical system comprising a support, a wearing part and a connection device between the wearing part and its support, in particular between a bucket tooth and its support that belong to a heavy-construction machine, the support comprising two orifices emerging on either side of a housing for receiving the connection device, the connection device comprising:

-   -   a key including a body that is elongated along the key axis         between a threaded foot and a head,     -   a nut capable of being screwed on the threaded foot of the key,         and     -   a sheath made from an elastically deformable material, arranged         around the body, provided with a first end pressed against the         head, a second end pressed against the nut, and a wall         adjustable by deformation in a housing of the support, by         screwing between the threaded foot of the key and the nut,         between an insertion configuration and a locked configuration of         the connection device.         The system is characterized in that:     -   each through orifice of the housing includes a first part         centered on a central axis of the housing and extending radially         over more than 180° around that central axis, and a second part         connected to the first part and radially offset relative to the         central axis,     -   in the insertion configuration, the connection device passes         through the second part of the orifices and does not exert a         locking force on the wearing part, and     -   in the locked configuration, the key axis is substantially         aligned with the central axis of the housing, the wall of the         sheath is adjusted in the housing, and the connection device         exerts locking forces on the wearing part.

The invention thus makes it possible to produce a rigid connection between the wearing part, in particular a bucket tooth, and its support, with considerable simplicity and high performance levels. Owing to the shape of the orifices emerging on either side of the housing formed in the support, the device can press the tooth against the support in the locked configuration. The key, the nut and the sheath are removable from each other in the insertion configuration and secured in the locked configuration. As a result, the connection device according to the invention is easy to manufacture and use. The mechanical system can be assembled and disassembled much more quickly and with a reduced risk of injury.

According to other advantageous features of the invention, considered alone or in combination:

-   -   The central axis is transverse to a fitting direction of the         wearing part on the support, preferably perpendicular to the         fitting direction.     -   The second part is centered on a secondary axis offset parallel         and radially relative to the central axis, the secondary axis         preferably being offset relative to the central axis in a         direction parallel to and opposite a fitting direction of the         wearing part on the support.     -   The wearing part comprises two bearing orifices that, when the         wearing part is fitted on the support, are each positioned         across from the second part of one of the through orifices of         the housing of the support, and in that in the locked         configuration, the connection device exerts locking forces in         the bearing orifices.     -   Each bearing orifice includes a recess in which either the head         or the nut is partially housed in the locked configuration.     -   In the locked configuration, the head and the nut are partially         framed, radially to the central axis of the housing, by the         first parts of the orifices.     -   A flat is formed on the nut, said flat being suitable for being         housed, at least in the insertion configuration, in the wearing         part.     -   The key has a center of gravity situated on the key axis.

The invention also relates to a heavy-construction machine bucket, comprising at least one mechanical system as described above. In practice, the bucket generally comprises a series of supports each receiving a tooth, which behaves like a wearing part and is secured to its support by a connection device.

Alternatively, other heavy-construction machine equipment may also be equipped with the mechanical system according to the invention.

Lastly, the invention relates to a method for implementing a mechanical system as described above. The method is characterized in that it comprises the following steps:

a) positioning the sheath around the body of the key;

b) positioning the nut on the threaded foot of the key;

c) positioning the wearing part on the support;

d) positioning the connection device in the housing of the support, in the insertion configuration where the connection device passes through the second part of the orifices and does not exert any locking force on the wearing part;

e) deforming the sheath in the housing by screwing the threaded foot of the key into the nut;

f) stopping the screwing in the locked configuration where the axis of the key is substantially aligned with the central axis of the housing, the wall of the sheath is adjusted in the housing and the connection device exerts locking forces on the wearing part.

The invention will be better understood upon reading the following description, provided solely as an non-limiting example and done in reference to the appended drawings, in which:

FIG. 1 is an exploded perspective view of a mechanical system according to the invention, comprising a support secured to a bucket that is partially shown, a wearing part, and a connection device for connecting the wearing part and the support, said connection device being shown in the locked configuration and comprising a sheath, a threaded key and a nut;

FIG. 2 is an exploded perspective view of the connection device;

FIG. 3 is an assembled perspective view of the connection device in an insertion configuration;

FIG. 4 is an assembled perspective view of the connection device in a locked configuration;

FIG. 5 is a side view along arrow V of FIG. 1, showing the mechanical system and the connection device in an insertion configuration;

FIG. 6 is a view similar to FIG. 5, showing the mechanical system and the connection device in a locked configuration;

FIGS. 7 and 8 are views similar to FIGS. 5 and 6, respectively, the wearing part not being shown;

FIGS. 9 and 10 are elevation views along arrow IX in FIG. 7 and arrow X in FIG. 8, respectively;

FIGS. 11 and 12 are cross-sections along line XI-XI in FIG. 9 and along line XII-XII in FIG. 10; and

FIGS. 13 and 14 are cross-sections along line XIII-XIII in FIG. 7 and along line XIV-XIV in FIG. 8, respectively.

FIGS. 1 to 14 show a mechanical system 1 according to the invention, equipping a heavy-construction machine bucket G.

The mechanical system 1 comprises an adapter-support 10, a wearing part 20 of the tooth type, as well as a connection device 30 between the support 10 and the tooth 20. The system 1 extends substantially along an axis X1, along which a first direction D1 for fitting of the tooth 20 on the support 10 is defined as well as a second direction D2, parallel to and opposite the first direction D1, for disassembling the tooth 20.

The bucket G is partially shown in FIG. 1, for simplification purposes. The support 10 is secured to the bucket G, while the tooth 20 is a wearing part designed to be disassembled when it is too worn by the operation of the bucket G.

The connection device 30 comprises a sheath 40, as well as a threaded key or screw 50 and a nut 60 positioned on either side of the sheath 40. The device 30 may be inserted into a housing 14 of the support 10, in an insertion configuration A shown in FIGS. 3, 5, 7, 9, 11 and 13. The relative screwing of the nut 60 and the key 50, in a direction of rotation R1, deforms the sheath 40 inserted between them, from the insertion configuration A to a locked configuration B shown in FIGS. 4, 6, 8, 10, 12 and 14.

Thus, the device 30 is adjustable between the insertion configuration A, where the sheath 40 is not in contact or is only partially in contact with the housing 14 while the device 30 does not exert any retaining force on the tooth 20, on the one hand, and the locked configuration B, where the sheath 40 is adjusted in the housing 14 of the support 10, while the device 30, more specifically the key 50 and the nut 60, bear against the tooth 20, thereby forming a coupling connection between the tooth 20 and its support 10.

To facilitate the identification of the different parts of the mechanical system 1 spatially, defined are: a front side 2 at which the tooth 20 is situated, a rear side 3 at which the support 10 is situated, an upper side 4 that is oriented opposite the ground when the system 1, a first side 5 for insertion of the device 30 into the support 10, and a second side 6 opposite the insertion side 5.

The support 10 comprises a base 11, partially shown in FIGS. 1 and 5 to 14, as well as a fitting nose 12 provided to be engaged in a cavity of the tooth 20 configured to that end. Furthermore, a housing 13 for receiving lugs 23 of the tooth 20 is formed on each side 5 and 6 of the base 11. Each housing 13 includes walls situated toward the rear 3, the top 4 and the bottom, and is open toward the front 2 so as to receive the lugs 23. The housing 14 extends through the nose 12, along an axis X14 perpendicular to the axis X1, between the sides 5 and 6. This housing is framed by the housings 13 on the sides 5 and 6.

Two orifices 16 are formed on the sides 5 and 6 in the nose 12, emerging on either side of the housing 14 along the axis X14. Each orifice 16 comprises a first part 17 and a second part 18 that are connected to each other. The part 17 is a half-cylinder that is centered on an axis X17 combined with the axis X14, closed over 180° toward the rear 3 and open at 180° toward the front 2. The part 18 is a cylinder portion that is centered on a secondary axis X18 that is off-centered relative to the axes X14 and X17, closed over more than 180° toward the front 2 and connected to the part 17 toward the rear 3. As shown in FIG. 7, the secondary axis X18 is offset radially and parallel to the axis X14, in the direction D2 opposite the fitting direction D1, according to a radial gap e18. The axes X14, X17 and X18 are situated in a same median plane Pm10 of the support 10. The orifices 16 globally have an oblong shape elongated along the axis X1. The part 18 delimits an opening with transverse dimensions larger than the opening delimited by the part 17, so as to facilitate the insertion of the device 30 in the housing 14 through the part 18 in the insertion configuration A, while the device 30 becomes housed in the part 17 in the locked configuration B.

In an alternative that is not shown, the orifices 16 may have a different shape suitable for the present application. For example, the part 17 may be a cylinder portion closed over less than 180° in the direction D1, in other words extending radially over more than 180° around the axis X14. According to another example, the part 17 may be a cylinder portion closed in a direction that is slightly inclined relative to the axis X1.

The tooth 20 comprises an active part 21 situated toward the front 2 and a hollow part 22 oriented toward the rear. In a known manner, the part 21 is provided to scrape and remove materials, for example dirt or gravel, while the part 22 is provided for fitting of the tooth 20 on the support 10. More specifically, the part 22 comprises the inner cavity, shown in FIGS. 1, 5 and 6, configured for fitting on the nose 12 of the support 10, as well as the lugs 23 that are oriented toward the rear and provided to be received in the housings 13, in contact with the top 4 and the bottom, as shown in FIGS. 5 and 6.

Orifices 24, each having a substantially cylindrical shape, are formed in each lug 23, on either side of the tooth 20 on the sides 5 and 6. These orifices 24 are positioned across from the part 18 of the orifices 16 when the tooth 20 is fitted on the support 10, thereby allowing the device 30 to be inserted in the housing 14, then allowing the device 30 to be used. Only the lug 23 and the orifice 24 situated on the side 5 are shown in FIGS. 1, 5 and 6. The lug situated on the side 6 is similar to the lug 23 situated on the side 5, while the orifice 24 situated on the side 6 is configured to receive the nut 60 provided with a flat 64, for example against a shoulder perpendicular to the axis X1. As shown in FIG. 1, the orifice 24 situated on the side 5 preferably comprises a recess 25, forming a possible favored bearing for the key 50. Alternatively, this orifice 24 and/or the recess 25 may have different shapes suitable for the present application. For example, the orifices 24 may have more or less elongated oblong shapes. Furthermore, the orifice 24 situated on the side 6 is preferably provided with a recess 25. The orifices 24 are provided to receive the device 30, more specifically the key 50 and the nut 60, bearing on the tooth 20 in the direction D1, in the locked configuration B described below.

The sheath 40 is made from an elastically deformable material, for example an elastomer. The sheath 40 is elongated between longitudinal ends 41 and 42 along a central axis X40. In the insertion configuration A, the end 41 is situated on the side 5, whereas the end 42 is situated on the side 6. This distinction is made for spatial identification purposes only, given that the ends 41 and 42 are reversible. The sheath 40 comprises a wall 43 that is centered on the axis X40 and curved radially opposite the axis X40. The wall 43 delimits an outer surface 44 forming an ellipsoid of revolution around the axis X40, truncated at the ends 41 and 42. The wall 43 also delimits an inner cavity 45, which is centered on the axis X40, emerging at the ends 41 and 42 and provided to receive the key 50, with a radial gap formed between the sheath 40 and the key 50. In practice, the housing 14 and the outer surface 44 have substantially complementary shapes in the locked configuration B, such that the wall 43 of the sheath 40 can be adjusted in the housing 14 of the support 10 by hugging its inner contours.

The key 50 is made from metal, for example steel. The key 50 comprises a body 53 elongated along an axis X50 between a head 51 and a threaded foot 52. More specifically, the head 51 comprises a hexagonal part 54 for being actuated by a tool, not shown for simplification purposes, a first cylindrical part 55 bearing in the orifice 24 of the tooth 20, a second cylindrical part 56 having a diameter smaller than the diameter of the part 55, and an annular shoulder 57 that is formed radially to the axis X50 between the parts 55 and 56 and faces the foot 52. The center of gravity of the key 50 is situated on the axis X50. With the exception of the threading of the foot 52 and the part 54, the key 50 is a piece of revolution around the axis X50, with no off-centered part.

The nut 60 is made from metal, for example steel similar to that of the key 50. The nut 60 comprises a first cylindrical part 61 bearing in the orifice 24 of the tooth 20, as well as a second cylindrical part 62 having a diameter smaller than the diameter of the part 61. The parts 61 and 62 are coaxial and centered on axis X60. The nut 60 also comprises an annular shoulder 63 that is formed radially to the axis X60 between the parts 61 and 62. The flat 64 is formed in the part 61, with a first planar face parallel and radially offset relative to the axis X60, as well as a second planar face perpendicular to the axis X60 and turned on the opposite side from the part 62. In other words, the flat 64 is open at the part 61, but not at the part 62, forming a stop for the nut 60 positioned in the lug 23 and the orifice 24 situated on the side 6 of the tooth 20. A tapping 65 is formed in the nut 60 along the axis X60, emerging at the part 62, but preferably not emerging at the part 61. The tapping 65 is complementary to the threading of the foot 52 of the key 50.

The operation of the connection device 30 equipping the mechanical system 1 is described below.

In a first step a), an operator positions the sheath 40 on the key 50. The body 53 is positioned in the cavity 45 and is surrounded by the wall 43, while the end 41 bears against the head 51.

In a second step b), the operator positions the nut 60 at the end of the key 50, with the shoulder 63 and the shoulder 57 facing each other. The tapping 65 is screwed on the threaded foot 52, with the sheath 40 inserted between the head 50 and the nut 60. The end 41 bears against the shoulder 57, while the end 42 bears against the shoulder 63. Furthermore, the wall 43 is adjusted radially to the axis X40, on the one hand on the cylindrical part 56 at the end 41, and on the other hand on the cylindrical part 62 at the end 42. The connection device 30 is then assembled, as shown in FIG. 3, with the axes X40, X50 and X60 combined. These axes are subsequently together designated using reference X50.

In a third step c), the operator positions the tooth 20 on the support 10, with the active part 21 oriented so as to be able to scrape and remove materials during operation of the system 1. The hollow part 22 is fitted on the nose 12, with complementary planes bearing against each other. The lugs 23 are received in the housings 13 of the base 11. The orifices 24 are placed across from the orifices 16 on the sides 5 and 6, such that the housing 14 is accessible to insert the device 30 in the insertion configuration A.

In a fourth step d), the operator positions the preassembled connection device 30 in the housing 14 of the support 10. The device 30 passes through the orifice 24, then the orifice 16 situated on the side 5, starting with the nut 60 and ending with the head 51, with the wall 43 of the sheath 40 slightly centripetally deforming as it passes through. The flat 64 of the nut 60 becomes housed in the orifice 24 situated on the side 6, while the head 51 is positioned in the orifice 24 situated on the side 5.

The device 30 is then in the insertion configuration A. The device 30, more specifically the key 50 and the nut 60, do not exert any retaining force on the tooth 20 in the direction D1, such that the relative positions of the support 10 and the tooth 20 are not locked. The device 30 passes through the part 18 of the orifices 16 and the key axis X50 is substantially aligned with the secondary axis X18. In other words, the axis X50 is offset radially and parallel to the central axis X14 of the housing 14, in the direction D2. Play is globally formed between the cylindrical part 55 and the part 18 of the orifice 16 situated on the side 5. That same part 55 is not in contact, or is only partially in contact, with the inner bore of the orifice 24 situated on the side 5. The outer surface 44 of the sheath 40 is not in contact, or is only partially in contact, with the surface of the housing 14. A length LA of the sheath 40 is delimited by the axial separation between the ends 41 and 42 of the sheath 40, in other words, between the shoulders 57 and 63 along the axis X50. Furthermore, a maximum diameter DA of the sheath 40 is delimited around the key axis X50 by the surface 44.

At this stage, the axes X14, X17, X18 and X50 are situated substantially in the median plane Pm10 of the support 10 containing the axis X1, as shown in FIGS. 5, 7, 9, 11 and 13. Nevertheless, except at the flat 64, the connection device 30 is released in the system 1. In other words, the axis X50 is mobile in and outside the plane Pm10.

In a fifth step e), the operator deforms the sheath 40 in the housing 14 by screwing the key 50 in the nut 60. More specifically, the operator uses a tool to exert a screwing torque, around the axis X50 in the direction of rotation R1, on the part 54 of the head 51, such that the threaded foot 52 penetrates the tapping 65. The nut 60 is kept abutting at the flat 64 in the orifice 24 situated on the side 6. The direction of rotation R1 may be identified by a marking, not shown for simplification purposes, on the head 51 of the key 50, so as to facilitate the operator's task.

Thus, the device 30 goes from the insertion configuration A to the locked configuration B. The rotation R1 of the key 50 gradually brings the head 51 closer to the nut 60, such that the sheath is compressed along the axis X50 between the shoulder 57 and the shoulder 63. The wall 43 deforms with an accentuation of its curvature in the middle part, i.e., an intermediate part between the shoulders 57 and 63. The outer surface 44 of the sheath 40 gradually bears against the inner wall of the housing 14, first on the front side 2, then on the sides 5 and 6 and on the rear side 3, as can be seen by comparing FIGS. 11 and 12. At the same time, the head 51 and the nut 60 translate in the direction D1, in the orifices 16 and 24 situated on the side 5 and the side 6, respectively. Thus, the axis X50 is offset in the direction D1, until it is substantially aligned with the central orifice X14 of the housing 14. The cylindrical parts 55 and 61 become housed in the corresponding part 17 of the orifices 16, until they bear against the orifices 24 and the recesses 25 in the direction D1.

Lastly, in a sixth step f), the operator stops the screwing of the device 30 in the locked configuration B. The key axis X50 is then substantially aligned with the central axis X14 of the housing 14. The device 30 passes through the part 17 of the orifices 16. The wall 43 of the sheath 40 is adjusted in the housing 14 of the support 10, with the surface 44 hugging the contours of the housing 14. A length LB of the sheath 40, which is smaller than the length LA, is delimited by the axial separation between the ends 41 and 42 of the sheath 40 along the axis X50. Furthermore, a maximum diameter DB of the sheath 40, which is larger than the diameter DA, is delimited around the key axis X50 by the surface 44. The deformation of the wall 43 is no longer possible, such that the sheath 40 has a compression strength, and therefore screwing strength, that is perceptible by the operator.

In the locked configuration B, the head 51 and the nut 60 exert locking forces on the tooth 20 in the direction D1, while the sheath 40 bears in reaction in the housing 14, forming a coupling link between the tooth 20 and the support 10. In particular, the locking forces exerted by the device 30 on the tooth 20 in the direction D1 are shown by an arrow F30 in FIG. 6. Advantageously, these forces F30 are distributed symmetrically relative to the plane Pm10. The head 51 and the nut 60 are framed on top 4 and bottom by the parts 17 of the orifices 16, so as to limit untimely movements transverse to the plane Pm10 during operation of the system 1. Furthermore, the sheath 40 is made from a deformable material rigid enough to prevent or reduce movements of the device 30 in the direction D2. Additionally, a metal insert can be molded in the wall 43 of the sheath 40. Under these conditions, tilting of the device 30 in the housing 14 is prevented in the locked configuration B.

Thus, when mechanical forces are exerted on the active part 21, the part 22 of the tooth 20 is firmly retained in the usage position simultaneously by the connection device 30 in the locked configuration B, by the nose 12, and by the walls of the housings 13 receiving the lugs 23.

Subsequently, in a disassembly step g), the operator can use the tool to unscrew the device 30 in a direction opposite the direction of rotation R1. The forces exerted by the device 30 on the tooth 20 and in the support 10 are released, from the locked configuration B toward the insertion configuration A. Next, the device 30 may be removed from the system 1, eliminating the coupling connection between the tooth 20 and the support 10. Thus, the device 30 allows the tooth 20 to be disassembled without a hammer, after wearing of said tooth, through operations opposite the mounting operations.

The component elements of the connection device 30 may be configured differently without going beyond the scope of the invention. In practice, the component elements of the device 30 are specifically designed to withstand the wear of the system 1 during operation, as well as to withstand several assembly and disassembly operations using the tool.

In an alternative that is not shown, the length of the key 50 along the axis X50 is such that neither the actuating part 54 nor the nut 60 protrude outside the orifices 24 of the lugs 23, when the system 1 is assembled. As shown in FIG. 10, the head 51 of the key 50 is then protected in the lug 23 of the tooth 20.

According to another alternative that is not shown, the part(s) for actuating the device 30 using one or more tools are configured differently. For example, the part 55 may include a circular or polygonal recess, open toward the outside on the side 5, facilitating the penetration of the tool. According to another example, the nut 60 may also be configured to be actuated by a tool on the side 6. In that case, for example, a cavity or a hexagonal rod may be formed on the part 61 instead of the flat 64.

According to other alternatives that are not shown, the housing 14, the orifices 16 and 24 and the axes X14 and X18 may be configured or arranged differently with respect to one another, as long as the device 30 exerts a sufficient locking force F30 on the tooth 20 in the locked configuration B. For example, the housing 14 may not be cylindrical, but may include planar bearing faces for the sheath 40. According to another example, the parts 17 and 18 of the orifices 16 may have shapes different from those of FIGS. 7 and 8, while being connected to each other. According to another example, the axis X14 of the housing 14 may not be perpendicular to the axis X1, but inclined in a transverse direction relative to the axis X1. According to one particular example, the axes X14 and X18 may be inclined by 10° or 20° relative to the axis X1. According to another example, the axes X14 and X18 may be perpendicular to the axis X1, both respectively situated on either side of the plane Pm10. In that case, preferably, the part 17 of the orifice is situated toward the bottom of the nose 12, while the part 18 is situated toward the top 4 of the nose 12.

According to another alternative that is not shown, the orifices 24 formed in the lugs 23 may include reinforced shoulders and/or thermal treatments of the contact areas with the key 50 and the nut 60, so as to have an increased surface hardness and facilitate locking of the device 30 in the locked configuration B. Furthermore, the nut 60 and the orifice 20 for receiving that nut 60 on the side 6 may be configured in any manner suitable for the present application, by allowing the screw 50 to be screwed in the tapping 65 to go from the insertion configuration A to the locked configuration B.

According to another alternative that is not shown, a metal insert may be arranged between the sheath 40 and the key 50, or may be molded directly in the wall 43.

Furthermore, the technical characteristics of the different embodiments may be combined with each other in whole or in part. Thus, the connection device may be adapted in terms of cost and performance. 

1-10. (canceled)
 11. A mechanical system (1) comprising a support (10), a wearing part (20) and a connection device (30) between the wearing part (20) and its support (10), in particular between a bucket tooth (20) and its support (10) that belong to a heavy-construction machine (G), the support (10) comprising two orifices (16) emerging on either side of a housing (14) for receiving the connection device (30), the connection device (30) comprising: a key (50) including a body (53) that is elongated along the key axis (X50) between a threaded foot (52) and a head (51), a nut (60) capable of being screwed on the threaded foot (52) of the key (50), and a sheath (40) made from an elastically deformable material, arranged around the body (53), provided with a first end (41) pressed against the head (51), a second end (42) pressed against the nut (60), and a wall (43) adjustable by deformation in a housing (14) of the support (10), by screwing (R1) between the threaded foot (52) of the key (50) and the nut (60), between an insertion configuration (A) and a locked configuration (B) of the connection device (30), wherein each through orifice (16) of the housing (14) includes: a first part (17) centered on a central axis (X14) of the housing (14) and extending radially over more than 180° around that central axis (X14), and a second part (18) connected to the first part (17) and radially offset relative to the central axis (X14), wherein in the insertion configuration (A), the connection device (30) passes through the second part (18) of the orifices (16) and does not exert a locking force on the wearing part (20), and wherein in the locked configuration (B), the key axis (X50) is substantially aligned with the central axis (X14) of the housing (14), the wall (43) of the sheath (40) is adjusted in the housing (14), and the connection device (30) exerts locking forces (F30) on the wearing part (20).
 12. The mechanical system (1) according to claim 11, wherein the central axis (X14) is transverse to a fitting direction (D1) of the wearing part (20) on the support (10).
 13. The mechanical system (1) according to claim 11, wherein the second part (18) is centered on a secondary axis (X18) offset parallel and radially relative to the central axis (X14), the secondary axis (X18) preferably being offset relative to the central axis (X14) in a direction (D2) parallel to and opposite a fitting direction (D1) of the wearing part (20) on the support (10).
 14. The mechanical system (1) according to claim 11, wherein the wearing part (20) comprises two bearing orifices (24) that, when the wearing part (20) is fitted on the support (10), are each positioned across from the second part (18) of one of the through orifices (16) of the housing (14) of the support (10), and in the locked configuration (B), the connection device (30) exerts locking forces (F30) in the bearing orifices (24).
 15. The mechanical system (1) according to claim 14, wherein each bearing orifice (24) includes a recess (25) in which either the head (51) or the nut (60) is partially housed in the locked configuration (B).
 16. The mechanical system (1) according to claim 11, wherein in the locked configuration (B), the head (51) and the nut (60) are partially framed, radially to the central axis (X14) of the housing (14), by the first parts (17) of the orifices (16).
 17. The mechanical system (1) according to claim 11, wherein a flat (64) is formed on the nut (60), said flat (64) being suitable for being housed, at least in the insertion configuration (A), in the wearing part (20).
 18. The mechanical system (1) according to claim 11, wherein the key (50) has a center of gravity situated on the key axis (X50).
 19. A heavy-construction machine bucket (G), comprising at least one mechanical system (1) according to claim
 11. 20. A method for implementing a mechanical system (1) according to claim 11, comprising the following steps: positioning the sheath (40) around the body (53) of the key (50); positioning the nut (60) on the threaded foot (52) of the key (50); positioning the wearing part (20) on the support (10); positioning the connection device (30) in the housing (14) of the support (10), in the insertion configuration (A) where the connection device (30) passes through the second part (18) of the orifices (16) and does not exert any locking force on the wearing part (20); deforming the sheath (40) in the housing (14) by screwing (R1) the threaded foot (52) of the key (50) into the nut (60); and stopping the screwing (R1) in the locked configuration (B) where the axis of the key (X50) is substantially aligned with the central axis (X14) of the housing (14), the wall (43) of the sheath (40) is adjusted in the housing (14) and the connection device (30) exerts locking forces (F30) on the wearing part (20). 